I recently updated to Ubuntu 9.10. The new Ubuntu version comes with a lot of new packages, including a new version of Java (6.16). Unfortunately, the newest Java plugin from Sun for Thunderbird depends on version 6.15. As a consequence, you’ll get an error message like the one below if you try to install the Java plugin. In this case when you try to open your BankID (which is a Java application). I have had a few problems with BankID on Ubuntu before as well.